Dispensers for aerosol formulations are in common use. In their simplest form, these dispensers comprise an L-shaped plastic device adapted at one end to receive an aerosol canister and terminating at the other end in a mouthpiece. These devices require that the user actuate the aerosol canister by manually depressing the canister, without any mechanical advantage, to the point of actuation. These simple dispensers such as that the disclosed in U.S. Pat. No. 3,001,524 provide no means to prevent accidental actuation, nor do they provide a means beyond friction fit of assuring that the aerosol canister remains in place during storage.
Dispensers with apparatus for closing the mouthpiece are known. There is disclosed in U.S. Pat. No. 4,637,528 a retractable, pivotable dispenser for aerosol formulations. The dispenser includes a removable cap for the mouthpiece which serves to protect the dispenser from dirt and dust when stored in the retracted position. Similarly, U.S. Pat. No. 4,292,966 discloses a retractable dispenser which in its retracted state has a flexible tongue covering the opening in the mouthpiece. In the elongated position the tongue is removed from the mouthpiece. These dispensers, however, provide no means to prevent unintended actuation of the aerosol canister if they are stored with the canister in place.
There exist aerosol dispensers which employ latch mechanisms to prevent accidental actuation. Disclosed in U.S. Pat. No. 4,664,107 is an inhalation-actuable dispenser wherein a latch mechanism prevents the actuation by inhalation absent the application of force by the user to the aerosol container. Untimely actuation and administration of an improper dose of medicament is thus prevented. Similarly, U.S. Pat. No. 3,732,884 discloses an inhalation-actuable dispenser comprising a gate which blocks actuation of the aerosol unless the user is inhaling through the device or unless the device is not in an upright position.
Unintended actuation has been prevented by other means as well. There is available from Sandoz an L-shaped dispenser wherein the aerosol container is stored in the mouthpiece and a dust cap covers the opposite end of the dispenser. Thus, the dispenser is protected from dust and dirt during storage, and unintended actuation is prevented. However, considerable assembly is required to take the dispenser from storage to use. This device is described on pages 1872-1873 of the Physicians' Desk Reference, 42nd Edition, 1988.
Last, U.S. Pat. No. 4,678,106 discloses a dispenser with a housing, a cover for the mouthpiece, and an actuator all pivotally connected to one another. When the cover is closed, the actuator can not be made to contact the canister, and actuation is prevented. When the cover is pivoted to the open position, the actuator is made to contact the canister and the canister may be actuated.